i'm loving ICS except for the battery issue. the other day i got in my car with my phone at 87%. when i got to where i was going 1 hour later, the battery was down to 72%--the only usage during that time was about 3 min on Google maps. i notice that wifi never sleeps (even if i set it to) when the phone sleeps...

I'm throwing this information in the mix NOT AT ALL to be a a braggard. As a matter of fact, I've had and HAVE my fair share of phone issues (have an EVO that had a RIDICULOUSLY horrible battery in the past). So I'm putting the following information out as a barometer/benchmark...

I received a brand new Nexus S 4G last week for a new line of service. I have NOT had a chance to set it up and put a bunch of "crap" on is like on my EVO but it is active and I have used it for a few calls. I was prompted to upgrade OTA from the shipped GB 2.3.7 OS to ICS 4.0.4 and did so. I have ChompSMS as my text messaging app, Jorte as my calendar synced with my Google account and that of another phone I have and various other apps that I downloaded. That being said I have NOTHING running in the background...no weather or news polling, no facebook or twitter or other update, not emails being checked. The only thing I have running and checking processes in the background is my Battery Monitor Widget.

I currently have 62% battery left and my phone has uptime of 2 DAYS, 3 HOURS....that is 51 HOURS. My Battery Monitor Widget indicates a drain of 0.2% per hour.

By means of comparison, my EVO with various network contacts, email polling and other data collection services (Minimalistic Text widgets, Words with Friends, Facebook, K-9 email (polls every couple hours, not that often) and a FEW weather services running at the same time) I typically get about 16 hours on a 2000 mAh Galilieo battery (upgrade from the 1500 or whatever the EVO stock is).

Again, I'm not showing off and I know, I know, I KNOW that I am hardly using my phone so I don't need anyone pointed that out. But I'm saying this to as a benchmark of comparison to show that the phone CERTAINLY can exhibit some fantastic battery capabilities and also to say that something other than ICS is likely calling people's battery issues.

Okay, to everyone following this post. I have figured out the intermittent battery drain. It is, in fact, exchange services. I have multiple email address' coming into this phone, and my work email is through an exchange. It seems like it is hanging open at times and severely draining the battery. I stop it and restart it and the drain goes away. I can tell when it happens because the phone starts getting hot. Each time it has done it over the past day, I have stopped exchange services and the phone cools off and the battery drain ceases. HINT HINT to all the sprint reps reading. Other than that, love the update. It does, however, need a remedy. Any help here would be greatly appreciated as when I don't catch it, it spits my battery life out like it was a bad habit.

Hello Gregg-O, Factory reset is the P.C. android term for hard reset, in short the means to erase all personal data in one quick action. and not to say this reset is necessary for all users upgrading to Ice cream sandwich it could prove useful for users that have inexplicable problems after the upgrade that they have been unable to resolve by managing their applications or settings. I have talked to a few people in my personal life that have upgraded recently, and they have reported similar performance to what was before the upgrade, a few have mentioned lowered battery life, but mentioned they have not looked at settings or apps being a cause.

I normally suggest start by disabling sync accounts, or auto sync for email accounts, remove active wallpapers, or widgets, disable wifi, 4g, bluetooth, GPS, NFC. to determine if the battery drain is less of a problem, if you have task killers, or security software try removing them.

Thank you for the info Dabbler32, I'm going to make sure this feedback gets to the right workgroup. Please try Juice Defender (free from the Play Store), and let me know if you see a dramatic improvement. Thank you, Chris.

Okay, to everyone following this post. I have figured out the intermittent battery drain. It is, in fact, exchange services. I have multiple email address' coming into this phone, and my work email is through an exchange. It seems like it is hanging open at times and severely draining the battery. I stop it and restart it and the drain goes away. I can tell when it happens because the phone starts getting hot. Each time it has done it over the past day, I have stopped exchange services and the phone cools off and the battery drain ceases. HINT HINT to all the sprint reps reading. Other than that, love the update. It does, however, need a remedy. Any help here would be greatly appreciated as when I don't catch it, it spits my battery life out like it was a bad habit.

Have you tried deleting the exchange account and adding it again, or possibly clearing all of the data for that email application? As with any software update, if there are inexplicable problem it could be due to a file that got updated that already was corrupted. The file may not have been actively used previously, but it got updated and started causing issues. I've had several dozen customers in my service and repair store with Nexus' after the update with weird issues, and clearing application data on the affected app has fixed most. Some required a factory reset due to multiple issues or system issues that weren't application-specific, but all of them have reported having similar or better battery life after the factory reset/data clearing, including those with Exchange servers setup.

The Nexus is no different than any other device when it comes to inexplicable issues after an update. Weird issues that aren't common often aren't an issue with the software itself but a weird upgrade glitch on that particular phone. Third-party applications can also potentially cause issues after updates.

Exchange is not the root cause of the battery drain at all. I have the battery drain issue on my NS4G phone and I have never used Exchange on the phone. I only have one personal Gmail account I use for email.

I took some of your advice and have improved the ICS operation. Actually all I did was discontinue the use of the Advanced Task Killer. That seemed to make a real impact especially it appears that there is a "task killer" built into ICS.

HOWEVER, there are a number of slow/sluggish operations. Especially <BACK> when in "nested" applications (switching into them using from Notifications

I beleive that wi-fi drains battery power more than before while it is searching for connections. Turning it off more often helps but it is hard to quantify.

All this I can live with BUT the big issue is the noticiably poor phone and data network reception, 3G/4G and wi-fi. This phone never had great reception - for example, sitting next to my laptop with 5 bars wi-fi, the Nexus S has 2 bars(bands), but ICS has made mine radically worse. I had simple connections problems in my local Barnes&Noble (wi-fi) and while in the car at a stop-light near a cell tower (with known good 3g)! I have yet to see any recommendations for improvement for the Nexus S and only complaints about ICS' negative affects.

I haven't even seen anectodal recommendations for improvements. @RC1024 - any ideas?

My husband and I both have Nexus S 4G phones which we have been very happy with until the last week after upgrading to ICS. What a mistake. Immediately after upgrading we found that: 1.All my calls and text messsages to him became blocked (although on my phone the texts showed that they were sent); 2.Voicemail on his phone became 'transcribed' text messages which were mostly gibberish as the voice recognition did not work well; 3.To answer any calls on both phones we must answer as usual, then wait for a female voice to 'announce' who is calling, get the keypad up on screen, and then press 1 to accept the call --all while the phone continues to ring, resulting in missed calls (THIS IS THE BIGGEST PROBLEM); 4.The typeface/ font becoming so small that my husband can no longer read it without his glasses; and 5.No way that we could find to change any of these settings. After several days of frustration, we ended up taking both phones to the local Sprint store for help. We spent several hours in the store waiting while our phones were 'worked' on, and left my phone there for most of the day to be further worked on (it was wiped clean and re-set). At the end of the day the only problem which was fully corrected is that I am now 'unblocked' from my husband's phone and can call and text him. His voicemail is now both 'regular' and transcribed (the technicians could not get rid of the transcribed versions). We both still have to answer calls, wait for the voice to announce them, and push '1' to answer. AND, there is no way to change the typeset/ font to make it more easily readable. I was told that these problems seem to be specific to both our phones only -and that no other customers had reported any similar problems. I asked if we could be switched back to gingerbread as neither of us had any problems before the upgrade, but was told no, it couldn't be done. I was also told that if I waited long enough, google would probably release an update which would solve our problems. As we both rely on our phones (and need them to be functional), the best fix offered was to sell our phones back to Sprint and switch to i-phones at an additional cost to us... I am wondering if anyone else has had similar problems with this upgrade as I find it a little odd that both of our phones, and ONLY our 2 phones whould have had these issues.